Zeeb Mohsen, Ganjali Mohammad Reza, Norouzi Parviz, Moeinossadat Seyyed Rezvan
Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
Talanta. 2009 Apr 30;78(2):584-9. doi: 10.1016/j.talanta.2008.12.015. Epub 2008 Dec 13.
In this work, an on-line system with vapor-phase generation (VPG) and Fourier transform infrared (FTIR) spectrometric detection has been developed as a direct and highly selective analytical technique for the assay of penicillamine (PA). Potassium iodate solution was injected into a reactor, heated at 75 degrees C, containing PA. The CO generated under these conditions was transported by means of N(2) gas carrier stream to an infrared gas cell and corresponding FTIR spectra were acquired in a continuous mode. The maximum absorbance of CO band at 2170 cm(-1), corrected by a baseline established between 2240 and 2000 cm(-1) at a nominal resolution of 2 cm(-1), was selected as a measurement criterion. Initially, the effect of different chemical, physical and spectroscopic parameters, such as concentration and volume of oxidant, pH, equilibrium time, reactor temperature, reactor volume, N(2) carrier flow rate and number of scans on the analytical signals were evaluated by using a short path length (10 cm) IR gas cell. At optimum experimental conditions, the method provided a relatively broad linear dynamic range of 4-380 mg L(-1), a limit of detection of 0.5 mg L(-1), a sampling frequency of 15 h(-1) and a relative standard deviation (R.S.D.) of 1.6%. Further, the method was successfully applied to the determination of PA in pharmaceutical formulations and results compared well with those obtained by a reference colorimetric method.
在本工作中，已开发出一种具有气相生成（VPG）和傅里叶变换红外（FTIR）光谱检测功能的在线系统，作为一种直接且高选择性的分析技术用于青霉胺（PA）的测定。将碘酸钾溶液注入到一个装有PA且加热至75℃的反应器中。在这些条件下生成的CO通过N₂气体载流输送至红外气室，并以连续模式采集相应的FTIR光谱。选择在2170 cm⁻¹处CO谱带的最大吸光度（在2240至2000 cm⁻¹之间以2 cm⁻¹的标称分辨率建立基线进行校正）作为测量标准。最初，使用短光程（10 cm）红外气室评估了不同化学、物理和光谱参数，如氧化剂的浓度和体积、pH值、平衡时间、反应器温度、反应器体积、N₂载气流速和扫描次数对分析信号的影响。在最佳实验条件下，该方法提供了4 - 380 mg L⁻¹相对较宽的线性动态范围、0.5 mg L⁻¹的检测限、15 h⁻¹的采样频率以及1.6%的相对标准偏差（R.S.D.）。此外，该方法成功应用于药物制剂中PA的测定，结果与参考比色法获得的结果相当。
